Pole bending apparatus

ABSTRACT

An apparatus for bending under pressure an ending portion of a long-sized hollow pole or a center portion of a short-sized hollow pole is described with which the occurrence of a crack at the seam portion of the pipe is avoided.

[ June 17, 1975 United States Patent [1 1 Sugita [56] References Cited UNITED STATES PATENTS POLE BENDING APPARATUS [75] Inventor:

Toshio Sugita, Sakura, Japan 27,672 3/1860 Nelson et 921,677 5/1909 Dcment 2,l08,27l 2/1938 Samuel 3,336,779 8/1967 Schall Primary ExaminerMiiton S. Mehr [57] ABSTRACT An apparatus for bending under pressure an ending mmm m WO rmm eil twt n r 6. 0 c n. ab .finm Owe 8 m .m. wh m 0 c wm 0 m n e bu e a s mm nnw O a nh OSM.$ Of .1 Pomp wmmm M72 7M WU fi m 97 M WW5 NW2 u./ "2 "7 Wmh "C r Na e S L C WM .m UhF Plum 555 4 Claims, 4 Drawing Figures POLE BENDING APPARATUS SUMMARY OF THE INVENTION The present invention relates to an apparatus for giving a desirable bend to a pole or a pipe. In the conventional method of bending a pole into an arc shape having a certain radius, a disc-like guide and a bending roller have been used. The bending roller moves concen trically around the disclike guide, and bends the pole or pipe into an arc-shape which was inserted between it and the guide. However, in such kinds of apparatus, it is impossible to bend a pole or pipe into a curved shape with more than one radius, for example, a curved shape consisting of plural radii. To succeed in the formation of a pole or pipe into such shapes as mentioned above, the bending works had to be carried out inefficiently with several difficulties.

The present invention has been developed in order to overcome the disadvantages of conventional arts mentioned above, and is to provide a pole bending apparatus for bending a pole held between the grooves of a curved guide and of a bending roller into the shape having a desirable curvature by means of that roller mounted on a truck movable on a curved rail which is provided in parallel or concentric relation with the curved guide having a desirable curvature with a certain space between them.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of a pole bending device according to the present invention.

FIG. 2 is a side elevational view of the main part of the apparatus as seen from the point A.

FIG. 3 is an elevational view of the truck.

FIG. 4 is a rear elcvational view of the truck.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The present invention will now be described hereinafter with reference to a preferred embodiment shown in the accompanying drawings.

A curved guide 1 having a desirable curvature is supported firmly by legs 15. A curved rail 2 is supported firmly by legs 16 in parallel or concentric relation with the curved guide 1 with a certain space between the two. A rack 3 is fixed on the internal side of the curved rail 2 in a longitudinal direction, and faces the curved guide.

A truck 4 which moves automatically on the curved rail 2 has a pedestal 4a which is mounted on the curved rail 2. The pedestal 4a is provided with a bending roller 5 which is opposed to the curved guide 1, and with a gear 6 engaged with the rack 3 on the curved rail 2. The bending roller 5 comprises a groove along its cylindrical surface in horizontal direction, and the curved guide 1 is also provided with a groove on the surface opposed to the bending roller in a longitudinal direction, so that the two grooves may form an approximately round opening to hold the pipe to be bent. Further, the pedestal 4a is provided with rollers 7, 8, 9, 10, 11, I2 and 13 in order to hold the curved rail 2 from four directions, i.e. upward, downward, right-hand and left-hand directions, so that the truck 4 movable on the curved rail can be firmly secured to it. A small gear 14 is engaged with the gear 6 to drive it at a reduced speed when a motor (not shown) mounted on the pedestal 4a of the truck 4 is actuated. In an embodiment having a technical construction described above, the rotation of the gear 6 engaged with the rack 3 at a reduced speed via the small gear 14 which is driven by the motor moves the truck 4 on the curved rail 2 along the curved guide 1, and thereby the pole held between the grooves of the guide 1 and of the bending roller 5 can be bent in the same curvature as the curved guide 1.

During the bending operation, the truck 4 is subjected to a strong force to push it outwardly, but it is supported so firmly on the curved rail 2 by the upper rollers 7, lower rollers 8, and the rollers 9, 10, 11, 12 and 13 at both sides of it that the truck 4 can be driven safely and smoothly, and the bending operation can be carried out efficiently.

According to the present invention, the bending work can be carried out efficiently not only for a straight pole or pipe but also for a tapered pipe.

Further, even poles or pipes having such a curved shape which consists of plural arcs can be produced only if the bending guide 1 and the curved rail 2 are installed with a certain and equal space between them.

According to the present invention, as described above, the curved rail is installed at the outside of the curved guide with a certain and equal space between them, and the bending roller is mounted on the truck movable on the curved rail by means of the gear engaged with the rack which extends on the internal side of the curved rail in a longitudinal direction. A pole or pipe inserted into and held between the grooves of the curved guide and of the bending roller, when the bending roller moves along the bending guide is subjected to a consistent pressure on the overall surface of the pole or pipe, whereby the bending work can be carried out safely without cracks occurring at the seam portion of the pipe to produce a pipe having the same curvature as the curved guide.

What is claimed is:

1. Pole bending apparatus comprising an inner guide member having a concave groove along its outer face and forming an elongated curve to which a pipe is to be bent, an outer rail member formed into a curve spaced from and paralleling that of the guide member and having a rack extending along its length, a movable truck member mounted on the outer rail member and having gear means engaging the rack on the rail member, a bending roller mounted on the truck and having a concave groove facing the concave groove on the inner guide member and forming therewith an approximately round opening for receiving and clamping the pipe to be bent, and means for driving the truck gear means causing the truck to move along the rail member whereby a pipe insertedinto the round opening is bent into a curve conforming to that of the inner guide member.

2. Pole bending apparatus as claimed in claim 1 wherein the rack extends along an inner face of the outer rail member.

3. Pole bending apparatus as claimed in claim 2 wherein the truck member comprises a pedestal, the bending roller is mounted on the pedestal, the rack engaging gear is mounted on the pedestal, and the truck driving means comprises another gear mounted on the pedestal.

4. Pole bending apparatus as claimed in claim 3 and further comprising plural rotary rollers mounted on said pedestal, said plural rotary rollers being located so as to clamp said rail member in two horizontal and two vertical directions. 

1. Pole bending apparatus comprising an inner guide member having a concave groove along its outer face and forming an elongated curve to which a pipe is to be bent, an outer rail member formed into a curve spaced from and paralleling that of the guide member and having a rack extending along its length, a movable truck member mounted on the outer rail member and having gear means engaging the rack on the rail member, a bending roller mounted on the truck and having a concave groove facing the concave groove on the inner guide member and forming therewith an approximately round opening for receiving and clamping the pipe to be bent, and means for driving the truck gear means causing the truck to move along the rail member whereby a pipe inserted into the round opening is bent into a curve conforming to that of the inner guide member.
 2. Pole bending apparatus as claimed in claim 1 wherein the rack extends along an inner face of the outer rail member.
 3. Pole bending apparatus as claimed in claim 2 wherein the truck member comprises a pedestal, the bending roller is mounted on the pedestal, the rack-engaging gear is mounted on the pedestal, and the truck driving means comprises another gear mounted on the pedestal.
 4. Pole bending apparatus as claimed in claim 3 and further comprising plural rotary rollers mounted on said pedestal, said plural rotary rollers being located so as to clamp said rail member in two horizontal and two vertical directions. 